Jasmine flowers smell great, but they don't make essential oils like some other flowers do. That's because they don't have many oil glands in their flowers, so there's not much oil. Also, the specific chemicals needed for making lots of essential oil might not be in jasmine. Even if there's a bit of oil, getting a lot of it out is hard. So, perfumers often use different ways, like synthetic fragrances or other natural floral scents, to get the lilac smell into their products. Even with these challenges, people still love the smell of jasmine, and it keeps inspiring the perfume world.

Once the fragrance was diluted at a concentration of 0,5µg/mL in the non polar solvant, it was analyzed by GC/MS.

GC-MS analysis is useful to identify and quantify the components of Fragrance oil with the following parameters:

Among these compounds, linalyl acetate and linalool; from the lavender essential oil, 2-hexyl cinnamaldehyde and D limonene; from the jasmine absolute, contribute to the floral and fruity top note.

Other molecules of the jasmine absolute, which are benzyl acetate and methyl dihydrojasmonate, bring the jasmine middle note.

Neither molecule clearly contributes to the musky and woody base note. However, because the GC/MS system can’t distinguish chirality from molecules, I hypothized that fragrance contains a mixture of the 2 enantiomeric form of limonene. In this case, L-limonene which has a piney scent would create the woody base note.

Then there are synthetic molecules such as DEHA and benzyl alcohol which don’t contribute in the smell of the product but only in the formulation. They are used to improve the durability of the fragrance oil by stabilizing it over time. Additionally, they can serve as a solvent, helping to dissolve and distribute compounds.

According to the commercial ingredients list on the safety data sheet of the jasmine fragrance, the commercial product contains 8 natural or synthetic ingredients, used for their properties, with a majority of Linalyl acetate (7-15%) and Octanal, 2-(phenylmethylene)- (5-10%). The linalyl acetate, 2-hexylcinnamaldehyde, linalool and benzyl alcohol were identified by GC/MS with valid concentrations within the official concentration range. However, fragrance contains principally 50.61% of DEHA and 10.50% of methyl dihydrojasmonate that are note referenced into the list of ingredients.

Let's take a closer look at these molecules.

• DEHA

DEHA is an industrial chemical that helps to improve the flexibility and durability of the fragrance oil, ensuring that it remains stable over time. Additionally, this additive can serve as a solvent, helping to dissolve and distribute the fragrance compounds evenly throughout the oil. DEHA is also a plasticizing agent to which we can be exposed using consumer products such as PVC packaging, cosmetics or via industrial releases into the environment during production operations. Nevertheless, it is a product recognized as dangerous by international health and environmental bodies.

Because the fragrance oil comes from the Candian market, let's take a look at the Canadian health service. From December 2006 to June 2010, scientific critically studies evaluated the risks of DEHA. This became a major challenge published in the Canada Gazette on 26 September 2009, and numerous studies described on the Government of Canada website were carried out. It emerged that this chemical could migrate from food packaging into food, that high levels of exposure can cause liver, reproductive and developmental effects and that it is a persistent environmental pollutant. DEHA has therefore been shown to be carcinogenic and harmful to the environment and biological diversity. Control of this substance has been deemed to be a high priority, and it is being closely monitored through the implementation of risk management measures. Some even believe that it should be included on Health Canada's Cosmetic Ingredient Hotlist. 

With this in mind, we can hypothized that the company does not list this toxic chemical additive to appear more ‘natural’ in order to maximize consumer confidence and protect the formulation receip from competing compagnies. Indeed DEHA is not an active ingredient for odor, it is quite likely that regulations will exempt secondary additives from the list of ingredients.

To complete the study and see if the fragrance can be toxic by inhalation, the headspace of the heated fragrance oil was analyzed by using the combination of the SPME extraction method with the GC/MS analysis system.

In a vial closed with parafilm and placed on a hot plate the fragrance is heated. For 10min the headspace is taken with an SPME needle. The analysis program was almost the same that the one for the fragrance oil analysis except for the temperature of the inlet, which has been lowered to 200°C to detect and not burn all the most volatile and delicate molecules.

My name is Emmy, I am 19 and I’m studying chemistry at the IUT of Montpellier in the south of France. Thanks to my institution I have the opportunity to carry out my internship at the University of Ottawa as a Visitor Research Student to take part in the Sharon Curtis Hydrosol project.

It’s a wonderful experience to develop chemical knowledge about odorant products, to gain more practical experience in analytical chemistry and to work in a multicultural environment with Sharon Curtis and some grad students in Paul Mayer’s lab.

All the knowledge I've gained is very fascinating and enriching in terms of realizing my dream of a career in perfumery.

I'm glad to have worked on Sharon's new research project around fragrance oils. My study focused on the smell of jasmine that is a signature of the hot Summer day on the Mediterranean coast where I grew up !